Protein Domain : Haemerythrin IPR002063

Type	Family
Description	The hemerythrin family is composed of hemerythrin proteins found in invertebrates, and a broader collection of bacterial and archaeal homologues. Hemerythrin is an oxygen-binding protein found in the vascular system and coelomic fluid, or in muscles (myohemerythrin) in invertebrates [ ]. Many of the homologous proteins found in prokaryotes are multi-domain proteins with signal-transducing domains such as the GGDEF diguanylate cyclase domain () and methyl-accepting chemotaxis protein (MCP) signalling domain ( ). Most hemerythrins are oxygen-carriers with a bound non-haem iron, but at least one example is a cadmium-binding protein, apparently with a role in sequestering toxic metals rather than in binding oxygen. The prokaryote with the most instances of this domain is Magnetococcus sp. MC-1, a magnetotactic bacterium.Hemerythrins and myohemerythrins [ , ] are small proteins of about 110 to 129 amino acid residues that bind two iron atoms. They are left-twisted 4-α-helical bundles, which provide a hydrophobic pocket where dioxygen binds as a peroxo species, interacting with adjacent aliphatic side chains via van der Waals forces []. In both hemerythrins and myohemerythrins, the active centre is a binuclear iron complex, bound directly to the protein via 7 amino acid side chains [], 5 His, 1 Glu and 1 Asp []. Ovohemerythrin [], a yolk protein from the leech Theromyzon tessulatum seems to belong to this family of proteins, it may play a role in the detoxification of free iron after a blood meal [].This entry represents the haemerythrin family of proteins.
Short Name	Haemerythrin